Hidden lunar mass under far-side basin could rewrite Moon's history

Using NASA’s GRAIL gravity data and LOLA topography, scientists found a massive, unusually dense mass buried hundreds of kilometers beneath the Moon’s South Pole–Aitken basin, weighing at least 2.18×10^18 kilograms and depressing the basin floor by about 1–2 kilometers; its origin could be iron–nickel core material from the impactor or dense oxide-rich material from a primordial magma ocean, with an offset of ~400 kilometers complicating simple histories. The finding sheds light on the Moon’s deep mantle and makes the far side an even more compelling target for future exploration.